Fabrication of filamentary field-emission device, including self-aligned gate

Claim 1

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a patterned lower electrically conductive region comprising a group of generally parallel lines situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region, the pores having an average diameter of no more than 200 nm; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region.

Claim 2

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a patterned lower electrically conductive region comprising a group of generally parallel lines situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region, the pores having an average diameter of no more than 200 nm; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region.

Claim 8

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; and subsequently providing a patterned electrically conductive gate layer over specified material of the porous layer, openings respectively extending through the gate layer at locations generally centered on the filaments such that the filaments are separated from the gate layer.

Claim 9

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; and subsequently providing a patterned electrically conductive gate layer over specified material of the porous layer, openings respectively extending through the gate layer at locations generally centered on the filaments such that the filaments are separated from the gate layer.

Claim 12

A method comprising the steps of: creating a structure in which a patterned electrically conductive gate layer is situated over a porous electrically insulating layer that lies over a lower electrically conductive region situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region, openings respectively extending through the gate layer at locations generally centered on the pores, each opening being wider than the corresponding pore; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region.

Claim 13

A method comprising the steps of: creating a structure in which a patterned electrically conductive gate layer is situated over a porous electrically insulating layer that lies over a lower electrically conductive region situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region, openings respectively extending through the gate layer at locations generally centered on the pores, each opening being wider than the corresponding pore; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region.

Claim 16

A method comprising the steps of: creating a structure in which an electrically insulating porous layer lies over a lower electrically conductive region situated over electrically insulating material of a substrate, the lower conductive region comprising a highly resistive portion and a highly conductive portion situated under the highly resistive portion, a multiplicity of pores extending through the porous layer down to the highly resistive portion; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the highly resistive portion.

Claim 17

A method comprising the steps of: creating a structure in which an electrically insulating porous layer lies over a lower electrically conductive region situated over electrically insulating material of a substrate, the lower conductive region comprising a highly resistive portion and a highly conductive portion situated under the highly resistive portion, a multiplicity of pores extending through the porous layer down to the highly resistive portion; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the highly resistive portion.

Claim 21

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a patterned lower electrically conductive region comprising a group of generally parallel lines situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; and providing an anode structure above, and spaced vertically apart from, the upper ends of the filaments for collecting electrons emitted from the filaments.

Claim 22

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a patterned lower electrically conductive region comprising a group of generally parallel lines situated over electrically insulating material of a substrate, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; and providing an anode structure above, and spaced vertically apart from, the upper ends of the filaments for collecting electrons emitted from the filaments.

Claim 30

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region; introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region. electropolishing the filaments to make them more uniform in length.

Claim 31

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region; introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region. electropolishing the filaments to make them more uniform in length.

Claim 39

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; and subsequently providing a patterned electrically conductive gate layer over specified material of the porous layer, openings respectively extending through the gate layer at locations generally centered on the filaments such that the filaments are separated from the gate layer.

Claim 40

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; and subsequently providing a patterned electrically conductive gate layer over specified material of the porous layer, openings respectively extending through the gate layer at locations generally centered on the filaments such that the filaments are separated from the gate layer.

Claim 51

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region, each pore containing an electron-emissive filament that contacts the lower conductive region at the lower end of the filament; producing electrically conductive caps over the upper ends of the filaments, each cap being situated over one of the filaments and having a lateral periphery that encloses the lateral periphery of the underlying filament along the bottom of that cap; removing part of the thickness of the porous layer; depositing electrically conductive gate material over the remainder of the porous layer in the space generally below the space between the caps; substantially removing the caps including any of the gate material on the caps, whereby the remaining gate material substantially forms a patterned gate layer through which openings respectively extend at locations generally centered on the filaments such that the filaments are separated from the gate layer; and removing portions of the porous layer exposed through the openings to form cavities around the filaments so that the filaments extend outward beyond the remainder of the porous layer, the cavities extending at least partway down to the lower conductive region.

Claim 52

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region, each pore containing an electron-emissive filament that contacts the lower conductive region at the lower end of the filament; producing electrically conductive caps over the upper ends of the filaments, each cap being situated over one of the filaments and having a lateral periphery that encloses the lateral periphery of the underlying filament along the bottom of that cap; removing part of the thickness of the porous layer; depositing electrically conductive gate material over the remainder of the porous layer in the space generally below the space between the caps; substantially removing the caps including any of the gate material on the caps, whereby the remaining gate material substantially forms a patterned gate layer through which openings respectively extend at locations generally centered on the filaments such that the filaments are separated from the gate layer; and removing portions of the porous layer exposed through the openings to form cavities around the filaments so that the filaments extend outward beyond the remainder of the porous layer, the cavities extending at least partway down to the lower conductive region.

Claim 55

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region, each pore containing an electron-emissive filament that contacts the lower conductive region at the lower end of the filament; producing electrically conductive caps over the upper ends of the filaments, each cap being situated over one of the filaments and having a lateral periphery that encloses the lateral periphery of the underlying filament along the bottom of that cap; depositing a blanket layer of electrically conductive gate material over the porous layer and the caps; selectively removing the gate material over the caps so as to expose them; substantially removing the caps, whereby the remaining gate material substantially forms a patterned gate layer through which openings respectively extend at locations generally centered on the filaments such that the filaments are separated from the gate layer; and removing portions of the porous layer exposed through the openings to form cavities around the filaments so that the filaments extend outward beyond the remainder of the porous layer, the cavities extending at least partway down to the lower conductive region.

Claim 56

A method comprising the steps of: creating a structure in which a porous electrically insulating layer lies over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region, each pore containing an electron-emissive filament that contacts the lower conductive region at the lower end of the filament; producing electrically conductive caps over the upper ends of the filaments, each cap being situated over one of the filaments and having a lateral periphery that encloses the lateral periphery of the underlying filament along the bottom of that cap; depositing a blanket layer of electrically conductive gate material over the porous layer and the caps; selectively removing the gate material over the caps so as to expose them; substantially removing the caps, whereby the remaining gate material substantially forms a patterned gate layer through which openings respectively extend at locations generally centered on the filaments such that the filaments are separated from the gate layer; and removing portions of the porous layer exposed through the openings to form cavities around the filaments so that the filaments extend outward beyond the remainder of the porous layer, the cavities extending at least partway down to the lower conductive region.

Claim 60

A method comprising the steps of: creating a structure in which an electrically conductive gate layer lies over an initial electrically insulating layer situated over a lower electrically conductive region, openings extending through the gate layer to expose corresponding surface portions of the insulating layer; subsequently forming a multiplicity of pores through the insulating layer down to the lower conductive region, each pore being formed through part of the exposed surface portion of a corresponding one of the openings such that each pore is generally centered on the corresponding opening and is considerably narrower than the corresponding opening along the bottom of the gate layer; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments separated from the gate layer, the lower end of each filament contacting the lower conductive region.

Claim 61

A method comprising the steps of: creating a structure in which an electrically conductive gate layer lies over an initial electrically insulating layer situated over a lower electrically conductive region, openings extending through the gate layer to expose corresponding surface portions of the insulating layer; subsequently forming a multiplicity of pores through the insulating layer down to the lower conductive region, each pore being formed through part of the exposed surface portion of a corresponding one of the openings such that each pore is generally centered on the corresponding opening and is considerably narrower than the corresponding opening along the bottom of the gate layer; and subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments separated from the gate layer, the lower end of each filament contacting the lower conductive region.

Claim 64

A method comprising the steps of: creating a structure in which an electrically insulating layer lies over a lower electrically conductive region, an electrically conductive gate layer lies over the insulating layer, and a further layer lies over the gate layer; causing charged particles to pass through the three layers to form a multiplicity of charged-particle tracks down to the lower conductive region, each track comprising (a) a first segment extending through the insulating layer and (b) a second segment extending through the further layer in line with the first track segment; etching the further layer along the second track segments to form corresponding apertures through the further layer down to the gate layer; etching the gate layer through the apertures to form corresponding openings through the gate layer down to the insulating layer such that each opening is generally centered on the corresponding aperture; etching the insulating layer along the first track segments to form corresponding pores through the insulating layer down to the lower conductive region; and introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments separated from the gate layer, the lower end of each filament contacting the lower conductive region.

Claim 65

A method comprising the steps of: creating a structure in which an electrically insulating layer lies over a lower electrically conductive region, an electrically conductive gate layer lies over the insulating layer, and a further layer lies over the gate layer; causing charged particles to pass through the three layers to form a multiplicity of charged-particle tracks down to the lower conductive region, each track comprising (a) a first segment extending through the insulating layer and (b) a second segment extending through the further layer in line with the first track segment; etching the further layer along the second track segments to form corresponding apertures through the further layer down to the gate layer; etching the gate layer through the apertures to form corresponding openings through the gate layer down to the insulating layer such that each opening is generally centered on the corresponding aperture; etching the insulating layer along the first track segments to form corresponding pores through the insulating layer down to the lower conductive region; and introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments separated from the gate layer, the lower end of each filament contacting the lower conductive region.

Claim 71

A method comprising the steps of: creating a structure in which a first electrically insulating layer lies over a lower electrically conductive region, an electrically conductive gate layer lies over the first insulating layer, a second electrically insulating layer lies over the gate layer, a second electrically conductive layer lies over the second insulating layer, and a further layer lies over the second conductive layer; causing charged particles to pass through the five layers to form a multiplicity of charged-particle tracks down to the lower conductive region, each track comprising (a) a first segment extending through the first insulating layer, (b) a second segment extending through the second insulating layer, and (c) a third segment extending through the further layer in line with the other two track segments; etching the further layer along the third track segments to form corresponding apertures through the further layer down to the second conductive layer; etching the second conductive layer through the apertures in the further layer to form corresponding openings through the second conductive layer down to the second insulating layer such that each opening through the second conductive layer is generally centered on the corresponding aperture through the further layer; etching the second insulating layer along the second track segments to form corresponding apertures through the second insulating layer down to the gate layer; etching the gate layer through the apertures in the second insulating layer to form corresponding openings through the gate layer down to the first insulating layer such that each opening through the gate layer is generally centered on the corresponding aperture through the second insulating layer; etching the first insulating layer along the first track segments to form corresponding pores through the first insulating layer down to the lower conductive region; and introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments separated from the two conductive layers, the lower end of each filament contacting the lower conductive region.

Claim 72

A method comprising the steps of: creating a structure in which a first electrically insulating layer lies over a lower electrically conductive region, an electrically conductive gate layer lies over the first insulating layer, a second electrically insulating layer lies over the gate layer, a second electrically conductive layer lies over the second insulating layer, and a further layer lies over the second conductive layer; causing charged particles to pass through the five layers to form a multiplicity of charged-particle tracks down to the lower conductive region, each track comprising (a) a first segment extending through the first insulating layer, (b) a second segment extending through the second insulating layer, and (c) a third segment extending through the further layer in line with the other two track segments; etching the further layer along the third track segments to form corresponding apertures through the further layer down to the second conductive layer; etching the second conductive layer through the apertures in the further layer to form corresponding openings through the second conductive layer down to the second insulating layer such that each opening through the second conductive layer is generally centered on the corresponding aperture through the further layer; etching the second insulating layer along the second track segments to form corresponding apertures through the second insulating layer down to the gate layer; etching the gate layer through the apertures in the second insulating layer to form corresponding openings through the gate layer down to the first insulating layer such that each opening through the gate layer is generally centered on the corresponding aperture through the second insulating layer; etching the first insulating layer along the first track segments to form corresponding pores through the first insulating layer down to the lower conductive region; and introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments separated from the two conductive layers, the lower end of each filament contacting the lower conductive region.

Claim 73

A method comprising the steps of: creating a structure in which a porous layer is situated over a lower electrically conductive region, a multiplicity of pores extend through the porous layer down to the lower conductive region, electrically conductive filament material is situated in the pores to form corresponding electron-emissive filaments, the lower end of each filament contacts the lower conductive region, a patterned electrically conductive gate layer is situated over the porous layer, and openings respectively corresponding to the filaments extend through the gate layer at locations generally centered on the filaments such that the filaments are separated from the gate layer; and subsequently sharpening the upper ends of the filaments to form sharpened tips.

Claim 74

A method comprising the steps of: creating a structure in which a porous layer is situated over a lower electrically conductive region, a multiplicity of pores extend through the porous layer down to the lower conductive region, electrically conductive filament material is situated in the pores to form corresponding electron-emissive filaments, the lower end of each filament contacts the lower conductive region, a patterned electrically conductive gate layer is situated over the porous layer, and openings respectively corresponding to the filaments extend through the gate layer at locations generally centered on the filaments such that the filaments are separated from the gate layer; and subsequently sharpening the upper ends of the filaments to form sharpened tips.

Claim 83

A method comprising the steps of: creating an electrically insulating layer over a lower electrically conductive region; subsequently forming charged-particle tracks through the insulating layer; etching the insulating layer along the charged-particle tracks to form a multiplicity of pores extending through the insulating layer down to the lower conductive region; and electrochemically introducing electrically conductive filament material into the pores starting from the lower conductive region to create corresponding electron-emissive filaments whose lower ends contact the lower conductive region.

Claim 84

A method comprising the steps of: creating an electrically insulating layer over a lower electrically conductive region; subsequently forming charged-particle tracks through the insulating layer; etching the insulating layer along the charged-particle tracks to form a multiplicity of pores extending through the insulating layer down to the lower conductive region; and electrochemically introducing electrically conductive filament material into the pores starting from the lower conductive region to create corresponding electron-emissive filaments whose lower ends contact the lower conductive region.

Claim 91

A method comprising the steps of: creating a structure in which a porous layer is situated over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; subsequently removing at least part of the thickness of the porous layer to enable each filament to extend outward beyond the remainder of the structure; and subsequently sharpening the upper ends of the filaments to form sharpened tips.

Claim 92

A method comprising the steps of: creating a structure in which a porous layer is situated over a lower electrically conductive region, a multiplicity of pores extending through the porous layer down to the lower conductive region; subsequently introducing electrically conductive filament material into the pores to form corresponding electron-emissive filaments therein, the lower end of each filament contacting the lower conductive region; subsequently removing at least part of the thickness of the porous layer to enable each filament to extend outward beyond the remainder of the structure; and subsequently sharpening the upper ends of the filaments to form sharpened tips.